Abstract Profectus Biosciences leverages its platform technologies of adjuvanted DNA vaccines to stimulate robust Th1- biased immune responses likely necessary for protection against challenging viral diseases such as HIV. We believe that optimized delivery methods are critical for development of effective genetic vaccines that can elicit these types of responses. Like others, we often deliver our DNA-based vaccines using electroporation. However, the logistical difficulties and pain associated with delivering vaccines via EP leads to doubt that it will ever be a realistic delivery modality for mass vaccination with prophylactic vaccines. For this reason, there is strong interest in development of alternative DNA delivery techniques. Ultrasound is a safe, non-invasive, effective method with which microbubbles can be used to propel attached or associated payloads into permeabilized target tissues. High acoustic ultrasound (well within FDA guidelines) of plasmid DNA with microbubbles induces unstable oscillation and ultimate collapse of the latter, leading to minor cell membrane disruption that allows the plasmid to enter nearby cells. Previous studies in animals have found ultrasound with microbubbles and plasmid DNA to promote protein production in targeted organs. Under this application, we will develop ultrasound-mediated gene transfer, or sonoporation, using microbubbles, as a painless replacement for electroporation. The ultrasound delivery platform will be developed using our well-established plasmid DNA vaccine, which encodes the HIV vaccine immunogen, Full-Length Single Chain (FLSC), and our IL-12 DNA adjuvant, as our ?model? vaccine. Although we will initially develop this sonoporation delivery technology for our HIV DNA vaccine, we believe that this same delivery technology will be suitable for virtually any DNA- or mRNA-based vaccine. Therefore, the development of this delivery technology should not only benefit the HIV vaccine field but the field of vaccinology in general. 2